16 September 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows two large and many small mesas composed of frozen carbon dioxide on the south polar cap of Mars. MGS has observed the south polar cap through three whole summers, and MOC images have shown that the scarps on these mesas retreat an average of 3 meters--some retreat faster, some a bit slower--per martian summer. The south polar cap is the most rapidly-changing landscape on Mars. These mesas are located near 86.5S, 358.5W. The image covers an area approximately 2 km (1.2 mi) across and is illuminated by sunlight from the upper left.